This application is a xc2xa7371 U.S. National Phase application which bases priority on International Application No. PCT/DE99/03944, filed Dec. 10, 1999, which in turn bases priority on German Application No. DE 198 59 628.6, filed Dec. 23, 1998.
1. Field of Invention
The invention relates to a device for preventing the penetration of corrosively acting salt particles into the generator and gear area of a wind power plant, particularly an offshore wind power plant.
2. Description of the Prior Art
Wind power plants designed for offshore use have a substantially encapsulated generator and gear area, which as a result of maintenance only being possible with considerable effort and cost, failure and maintenance risks are reduced to a minimum.
A particular problem for offshore use is the naturally existing salt-containing air, which can penetrate in small amounts, past seals into the interior, where it forms in the long term salt-containing, and consequently, hygroscopic lubricating films which, due to their electrically conductive properties, can give rise to short-circuits in control and monitoring installations, while also giving rise to corrosion problems.
The problem of the invention is to prevent the formation of such corrosively acting films in that salt particles are prevented from penetrating.
According to the invention this problem is solved by a device having the features of the main claim. The sub-claims give advantageous embodiments.
Instead of providing an ever more complicated seal which, if it has to be opened is still accessible to the ambient air, it is proposed by using air generating means to introduce air under an over pressure into a substantially encapsulated generator and gear area. Use is preferably made of an air pressure generator and a filtering device for separating liquid and salt particles, so that during operation in continuous manner drier and salt particle-free air is introduced, which prevents the formation of lubricating films, and simultaneously as a result of the over pressure created, prevents the unintentional penetration of external air through small gaps with a countercurrent.
Said filtering device can be a turbulence chamber, upstream of which is located an air compressor. In the turbulence chamber the air flows in a rapid circular path and must centrally leave the turbulence chamber counter to the centrifugal force. However, water or salt particles are deposited on the outer edge through centrifugal force and can then be removed.
In an alternative embodiment, in the case of an air inlet located on the back of the wind power plant, long depositing or settling hoses using the wind power plant tower length with a collecting device provided on the bottom can deliver the air into an over pressure zone in the generator and gear area.
It is also proposed to provide a pressure sensor making it possible by means of a remote control to monitor the necessary air pressure generation. If e.g. the necessary capacitor of a compressor rises or if in spite of the full capacity the compressor is unable to maintain the pressure, this enables conclusions to be drawn concerning the state of the compressor or the sealing of the generator and gear encapsulation.
Morever, in the case of high outside air speeds, it could be appropriate to increase the pressure in the generator and gear area. Any salt particles then penetrating through the higher external pressure are prevented from forming lubricating films in the interior by the dried air passing out as a result of the higher pressure prevailing in the interior.
Further, hollow components of the wind power plant could also be placed in this way under pressure.
A device operating with no electric power supply with e.g. a flow-caused air inlet port building up a dynamic pressure and/or an air outlet port building up a suction vacuum, would be implementable in a very operationally reliable manner without great additional cost.